1. Field of the Invention
The present invention relates to a massage apparatus, and more particularly, to such apparatuses that are installed in the back rest of a chair.
2. Description of the Related Art
Massaging mechanisms of many different designs have been designed in the past that are installed in the back rest of chairs. One of these designs is disclosed in U.S. Pat. No. 4,422,448; issued to Sugai. The massaging mechanism is moved vertically with rack 37 and pinion 41. Upward and downward massage is provided depending on the rotation of massaging wheels 45, which in turn depends on the rotation of feed shaft 47. The massage provided by this complicated mechanism is basically the same for both directions of rotation of shaft 47.
In U.S. Pat. No. 4,149,531 issued to Tanaka et al a vertical elongated screw bar 17 is disclosed and is driven by a motor through a V-belt and pulleys transmission. Roller assembly 3 is driven up and down by screw bar 17. Again the motor only provides one type of massage and a substantial portion of the mechanism would have to be replaced to obtain a different type of massage.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem of using one motor to provide only one type of massage in an efficient and economical way. None of these patents suggest the novel features of the present invention.